Washing apparatus for permanent press fabrics



Dec. 29, 1970 ANTHONY ETAL 3,550,171

WASHING APPARATUS FOR PERMANENT PRESS FABRICS 2 Sheets-Sheet 1 Filed Sept. 26, 1968 Dec. 29, 1970 ANTHONY ETAL 3,550,171

WASHING APPARATUS FOR PERMANENT PRESS FABRICS Filed Sept. 26, 1968 2 Sheets-Sheet 2 my. 2 60 l SEQUENTIALLY OPERATED SWITCHES CONTACTS CLOSED) CONTACT 5 IO United States Patent O 3,550,171 WASHING APPARATUS FOR PERMANENT PRESS FABRICS Tad B. Anthony and William H. Hunter, Newton, Iowa,

assignors to The Maytag Company, Newton, Iowa, a

corporation of Delaware Filed Sept. 26, 1968, Ser. No. 762,707 Int. Cl. D06f 33/02, 35/00, 23/04 US. Cl. 8-158 Claims ABSTRACT OF THE DISCLOSURE A fabric washing apparatus including control means operable for controlling the washing apparatus through a liquid cool-down sequence initiated at a predetermined low liquid level under control of a pressure sensing switch, maintained through a predetermined period of slow speed fluid extraction, and terminated after a period of agitation.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to automatic fabric washing machines and more particularly to a machine operable through a washing liquid cool-down sequence prior to the high speed centrifuging operation for achieving an improved sequence of operations for washing permanent press or wash and wear articles.

Description of the prior art It is common in the operation of automatic fabric washing machines to provide for a washing operation using warm or hot liquids to effect the cleansing of the fabrics. This high temperature wash operation is followed by a centrifugal liquid extraction operation and then by a rinse operation to remove the washing liquid from the fabrics and then in turn followed by a final liquid extraction operation. It has been found that the high temperature washing operation is most effective in achieving optimum cleansing of the fabrics and that the high temperature is effective for releasing wrinkles that have formed during prior wearing of the newer synthetic fabrics commonly called permanent press or wash and wear.

If, however, the synthetic fabrics are subjected to a high speed liquid extraction operation following the high temperature washing operation, the compacting of the fabrics against the inner periphery of the rotating fabric basket causes wrinkling of the synthetic fabrics that become relatively fixed and diflicult to remove. Previous work in the washing of synthetic fabrics has shown that it is desirable to reduce the temperature of the washing liquid for reducing the temperature of the fabrics being washed. A cool-down operation prior to the centrifugal extraction of liquids from the fabrics effectively achieves this end.

Prior art patents indicate a continuing search for improved methods and means for achieving a cool-down operation in an automatic washing machine. For example, Hughes, U.S. Pat. 3,055,202 proposes a system for alternately effecting partial emptying of the liquid container and refilling with cold water through a timed period after which the washing machine is operable for continuing the spinning operation to effect removal of the liquid from the fabrics. Billings et al. US. Pat. 3,078,700 on the other hand provides an overflow operation at the end of the wash operation to reduce the temperature of the water prior to the high speed fluid extraction. Billings et al. is directed to a system for preventing a spinning operation while the liquid is above a predetermned temperature.

3,550,171 Patented Dec. 29, 1970 In addition, a prior washing apparatus produced by The Maytag Company, assignee of the instant invention, as Model 160, included a wash and wear cycle having a liquid cool-down sequence. The cool-down sequence included a predetermined period of time for liquid removal followed by a cold water refill and an agitate period preceding the high speed extraction of the washing liquid. There were certain disadvantages associated with this prior cool-down sequence, however. For example, it was relatively difiicult to establish a predetermined time period suitable for removing sufficient washing liquid to achieve a proper cool-down while avoiding removing too much and thus allowing extraction to reach a high speed prior to the introduction of cold water. As a result, there were possibilities that with some loads the washing water would remain too hot going into the high speed fluid extraction or that with other loads too much washing fluid was removed, thus permitting the extractor to accelerate to a relatively high extraction speed prior to the introduction of cold water.

SUMMARY OF THE INVENTION It is an object of the instant invention to provide a fabric washing apparatus operable through an improved cool-down sequence prior to the centrifugal extraction operation of the washing fluid.

It is a further object of the instant invention to provide a fabric washing apparatus having an improved cool-down operation including agitation of the fabrics in lower temperature Washing liquid prior to centrifugal extraction of the washing liquid.

It is a still further object of the instant invention to provide a fabric washing machine having an improved fabric cool-down sequence wherein the cool-down sequence is initiated by liquid level sensing means, maintained through a predetermined period of fluid pump-out, and terminated after agitation in lower temperature washing liquid.

The instant invention achieves these objects in a fabric washing machine having a control system including selectively energizable programming means and liquid level sensing means. These control elements are cooperable in a control circuit and upon initiation by the programming means the liquid level means is operable for initiating the cool-down sequence prior to or during an initial portion of the extraction operation following a high temperature washing operation. The cool-down sequence includes a predetermined period of relatively low speed operation to remove a portion of the hot liquids, at least one refilling with cold liquid, and a period of agitation of the fabrics in the cooled down washing liquid.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a fabric washing machine with portions broken away and partially sectioned to illustrate elements of the washing machine and the instant invention;

FIG. 2 is a schematic diagram of an electric control circuit incorporating the instant invention and useful With the washing machine shown in FIG. 1;

FIG. 3 is a diagrammatic view showing the sequential switching of the programming means shown schematically in FIG. 2 and operable through the improved sequence of operations of the instant invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown an automatic washing machine 10 including a base frame 11 supported on a plurality of adjustable leg members 14 and mounting a cabinet enclosure 15 comprising sidewall portions 16 and a top cover portion 18. The top cover portion 18 includes a hinged door panel 19 normally covering a recessed loading opening 20 and further includes an upwardly extending housing 21 for accommodating various control members, such as programming means 24.

Mounted within the cabinet is a tub assembly 25 nutationally supported on the base frame 11 by a tripod arrangement including tub braces 26 which are connected to a generally imperforate outer liquid container or tub at their upper ends. Revolubly mounted within the imperforate outer tub 28 is a perforate clothes basket 29 in which is positioned an oscillatable agitator 30 for effecting movement of fabrics and water within the tub assembly 25. The outer imperforate tub 28 and the perforate clothes basket 29 are substantially aligned with the loading opening in the top cover 18 for permitting the operator to place fabrics within the basket 29 and to remove them upon completion of the cycle.

The base frame 11 also supports a reversible drive motor 31 operable for selectively effecting oscillation of the agitator 30 or centrifugal rotation of the inner basket 29 through the transmission assembly 34. The motor 31 is operable through a belt drive arrangement (not shown) and through the transmission 34 to effect in one direction of operation the oscillation of the agitator 30 and operable in the other direction to effect centrifugal rotation of the fabric basket 29. The transmission 34 and the belt drive arrangement effectively provide a slipping clutch or torque limiting means between the motor and the rotatable basket 29.

The construction and mounting of the tub assembly and the operation of the inner basket 29 and agitator are more clearly and specifically shown in the following patents, each of which is assigned to the assignee of the instant invention: Scott et al., U.S. 2,854,297; Smith et al., U.S. 2,926,136; Burkland, U.S. Re. 25,157; and Goodlaxson, U.S. 3,013,645.

The base frame 11 also supports a pumping means 35 that is driven by the motor 31 and which communicates through a flexible conduit 36 with the outer tub 28. This pump 35 is operable for carrying fluids from the outer tub 28 and pumping them toward an external drain through a drain hose 38 when the motor 31 is operated in the direction for effecting centrifugal rotation of the basket 29. More detailed description of the operation of the fluid pumping system is shown in Smith U.S. Re. 25,125, also assigned to the assignee of the instant in vention.

Various liquid control elements are provded on the tub assembly 25 and include a water inlet conduit 39 through which water may be selectively introduced into the washing basket 29 and outer tub 28. Water level sensing means is provided and includes a tube 40 in connection with the outer tub 28 at the sidewall toward the lower portion of the tub as in FIG. 1.

Referring to the schematic electric circuit of FIG. 2, the motor 31 corresponds to the portion of the circuit enclosed within the broken line and includes a low speed winding 50, a high speed winding 51, a start winding 54, and a pair of centrifugally operable switches and 56. At a predetermined speed, switch 55 opens to remove start winding 54 from the circuit and switch 56 operates between high speed winding 51 and low speed winding 50. The programming means or mechanism 24 is shown schematically in FIG. 2 as a plurality of contacts 60 through 74 operable in pairs under control of cam means (not shown). Each cooperating pair of contacts function as a sequentially operable switch. The switch 79 is in the power line 80 and serves as a line switch or an on-off switch. The liquid level sensing means is in the form of a pressure switch communicating with the tube 44 in FIG. 1 and having a switch member 81 operable between a first contact 84 with a predetermined high liquid level corresponding to a normal full tub of liquid as indicated by broken line 42 in FIG. 1 and a second contact 85 corresponding to a predetermined lower liquid level representing a switch reset position and indicated generally, at a static condition, by broken line 44 in FIG. 1.

The circuit further includes valve means 87 for controlling the incoming water and includes a pair of coils 88 and 89 selectively energizable to provide either cold or hot water to the fluid inlet conduit 39 shown in FIG. 1. In addition to being sequentially controlled by contact pairs 70-71, 71-72, and 73-74, the water valve solenoids 88 and 89 are controlled by a pair of manually operable switches 90 and 91 to selectively control the wash and rinse temperatures entering the washing container 28. A first switch 90 is operable between one of two contacts and is coupled with a second switch 91. The second switch 91 is effectively operable between open and closed positions.

Also included in FIG. 2 is a motor speed control switch 94 operable between a first contact 95 for effecting slow speed operation of the motor and a second contact 96 operable for effecting high speed rotation of the motor 31. It is assumed for this discussion that high speed operation has been selected as shown by the position of switch 94 made to contact 96.

Direction of motor rotation is controlled by contact pairs 64-65, 65-66, 67-68, and 68-69. When contact pairs 64-65 and 67-68 are closed the start winding 54 is so energized as to effect operation of the motor 31 in a direction for rotating basket 29 and operating the pump 35 for draining liquid from tub 28. When contact pairs 65-66 and 68-69 are closed the motor is energized for rotation in a direction for operating the agitator 30.

Referring to FIG. 3, there is shown a diagrammatic representation of the sequencing control of the programming means in which each of the increments 1 through 25 represent an increment of time of a programming means such as a cam timer and may each be of one minute duration, for example. A detailed analysis of FIG. 3 taken 'with the circuit of FIG. 2 will show a person skilled in the art that the washing apparatus of FIG. 1 will be operable through a sequence of operations to a permanent press cycle comprising the following:

Increments: Operation of the machine 1 .Off.

2-10 .Washing operation with hot liquid and agitator operating.

11 .Pause for reversing direction of motor rotation.

12-14 .Cool-down sequence including cooldown agitate.

15 .Pause for reversing direction of motor rotation. 16-17 .High speed extraction of Wash liquid. 18 .Pause for reversing direction of motor rotation. 19 .Deep rinse with motor operating to oscillate the agitator.

20 .Pause for reversing direction of motor rotation.

21-23 .Final high speed centrifugal extraction.

24-25 .Olf.

The instant invention is directed to the cool-down operation provided in increments 12-14. Upon advancement of the programming means 24 by a timing motor 100, for example, into increment 12, the position of the camoperated programming switches of FIG. 2 will be as follows: Contact pairs 60-61, 65-66, 68-69, and 70-71 will be open whereas contact pairs 62-63, 64-65, 67-68, 71-72, and 73-74 will be closed. Since a high temperature washing operation has just been completed, the water level switch 81 will be operated to the contact 84 indicating a full water condition. It is therefore possible to determine that the water valve 87 is de-energized,

and the timer motor 100 and the main drive motor 31 are energized through the switch 81 made to contact 84.

Energization of the drive motor 31 during increment 12 effects rotation of the fabric basket 29 and operation of the pump 35 to remove liquid from the outer tub 28. Because of the torque limiting drive and full tub of water and since only a portion of the liquid is removed, rotation of the inner basket 29 in the liquid will be limited because of the drag of the basket in the water to a relatively slow speed. Upon the emptying of a portion of the liquid, the level sensing switch 81 will operate to the low level contact 85 for de-energizing motor 31 and timer motor 100 and energizing the Water valve 87. Since timer contact pairs 71-72 and 73-74 are made, the cold water solenoid 88 is energized for eifecting a refilling of the liquid container 28 with cold water. This cold water will reduce the temperature of the liquid within the outer tub 28. When the liquid within the tub 28 reaches the predetermined full level, the level sensing switch 81 will operate from the low level contact 85 to the full contact 84 to again re-energize the motor 31 and timer motor 100 for effecting slow rotation of the fabric basket 29 and operation of pump 35. This liquid removal portion will be followed by an additional refill with cold water. This alternating removal of washing water and the addition of cold water will continue until the accumulated time of operation of motor 31 and timer motor 100 equals the full increment, such as one minute, for example. The timer motor 100 will then advance the programming means into increment 13 for a pause to effect conditioning of the motor for rotation in the opposite direction. In addition, if after the low speed spinning stops, the fluid level is sufliciently below the level 44 to effect a resetting of switch 81 to contact 85, the container will be filled with liquid after which the timer motor will be re-energized to advance out of increment 13.

In the 14th increment, contact pairs 64-65 and 67-68 are open and contact pairs 65-66 and 68-69 are closed to condition motor 31 for energization for operating agitator 30. Since the timer motor 100 was energized through switch 81 made to contact 84 for advancing out of increment 13, motor 31 and timer motor 100' will likewise be energized during increment 14 except that motor 31 will be energized for agitation. After the increment of agitation of the fabrics in a full or at least substantially full container of cooled down wash liquid, the programming means advances out of the 14th increment to terminate the cool-down sequence. A high speed extraction of the cooled down wash liquid, a normal rinse and a high speed extraction of the rinse liquid follows.

More specifically, the circuit operation during the cooldown sequence is as follows: At the beginning of the 12th increment, a circuit is completed for energizing the motor 31 from power line 80 through switch 79, and a conductor 101 to the liquid level sensing switch 81 and through the full contact 84 and a second conductor 104 to a junction 105. From the junction 105, the circuit continues through a conductor 106, timer contact pair 62-63, the speed switch 94, and contact pairs 65-66 and 67-68 to the motor 31. The other side of the motor 31 is connected to the neutral line 107. The motor will thus operate the pump and rotate the basket.

Upon operation of the level switch '81 from full contact 84 to the low level contact 85 after a portion of the wash liquid is removed, the circuit to the motor 31 is broken and a circuit is completed to the water valve 87 through the level switch 81 made to contact 85 and through the conductor 108, and timer contact pairs 73-74 and 71-72. The circuit continues through conductor 109 to the coil 88 for opening the cold water inlet. The opposite side of the cold solenoid 88 is connected to the neutral line 107. After the liquid rises to the full level, the switch 81 will operate from contact to contact 84 for de-energizing the valve 87 and reenergizing the motor 31 and timing motor This alternate energization of the motors 31 and 100 and the valve 87 will continue for the period of accumulated energization of the motors equal to the time period for increment 12.

In the 13th increment, it is seen that timer contact pairs 60-61 and 62-63 are open and since pressure switch 81 is closed to full contact 84 it may be determined that only timer motor 100 will be energized. This increment thus provides a pause for conditioning the motor 31 for a reversal of rotation upon advancement into increment 14. It will be noted in FIG. 3 that contact pairs 64-65 and 67-68 are opened upon advancement into the 13th increment and that contact pairs 65-66 and 68-69 are closed upon advancement into the 14th increment for conditioning the motor 31 for rotation in its direction for operating the agitator to facilitate movement of fabrics within the washing fluid.

At the beginning of the 14th increment, a circuit is completed for energizing the motor 31 from power line 80 through switch 79 and a conductor 101 to the liquid level sensing switch 81 and through the full contact 84 and a second conductor 104 to the junction 105. From the junction 105, the circuit continues through the conductor 106, timer contact pair 62-63, and the speed switch 94 to the motor 31. The motor will thus operate to eflect movement of the agitator within the basket. The agiation of the fabrics within the cooled down wash water will continue through the 14th increment and upon completion thereof the cool-down sequence will be terminated. Normal high speed extraction of the wash liquid from the fabrics will follow.

It is therefore seen that this cool-down sequence is effective for achieving an efficient and assured cool-downnot only of the liquid but of the fabrics contained therein.-

Such a system including agitation of the fabrics within the cooled down washing liquid prior to extraction of the washing fluids by centrifugal extraction is nowhere shown in the prior art.

While the liquid level sensing means shown is in the form of a pressure-operated switch 81, it is recognized that other liquid level sensing devices may be provided within the liquid container 28 and operable in the instant invention. Alternate devices may be operable for sensing a first relatively high fluid level corresponding to a normal full level of liquid and for sensing a second relatively lower liquid level. The lower level will be sufliciently above an actual empty condition to effectively prevent high speed spin of the fabric basket during the liquid removal portion of the cool-down sequence through operation of the torque limiting means and the drag of the liquid on the rotating basket.

It should be noted that the sequential programming control shown in FIG. 3 is indicated as extending from increments 1 through 25. These increments may be provided either as an individual timer separate from another timer operable for controlling other cycles of operations or they may be provided as a portion of the total available increments on a cam timer that also includes additional increments for controlling other cycles of operations. It would also be possible to superimpose these increments for a permanent press cycle on the cam control covering other cycles of operation. If the cycle control shown in FIG. 3 were to be superimposed on a cycle of operations useful in controlling regular cycles of operations, it would be necessary to insert additional manually operable switches to provide selectability of the permanent press cycle including a cool-down sequence.

In the drawings and specification, there has been set forth a preferred embodiment of the invention and although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in form and the proportion of parts as well as the substitution of equivalents are contemplated,

7 as circumstances may suggest or render expedient, Without departing from the spirit or scope of this invention as further defined in the following claims.

We claim:

1. A method of Washing synthetic fabrics comprising agitating said fabrics in a container having a predetermined level of relatively high temperature washing liquid to effect a washing of said fabrics; alternately removing washing liquids from said container and introducing low temperature liquid into said container for reducing the temperature of said washing liquid while maintaining the liquid level in said container above a predetermined lower liquid level, said liquid removing operation and said liquid introduction operation being continued for a predetermined accumulated period of liquid removing time; agitating said fabrics in the lower temperature washing liquid following completion of the liquid removing and liquid introduction operations to assure a reduction in the temperature of said fabrics; and centrifugally rotating said container to effect a removal of Washing liquid from said container and from said fabrics.

2. A method of Washing synthetic fabrics comprising agitating said fabrics in a container of relatively high temperature washing liquid to effect a Washing of said fabrics; removing a predetermined portion of the washing liquid from said container; introducing low temperature liquid into said container to reduce the temperature of the Washing liquid contained therein; repeating said liquid removal and said low temperature liquid introduction through a predetermined accumulated period of liquid removal; agitating said washing fluids and said fabrics for a period of time suflicient to effect a thorough mixing of said low temperature liquid with said washing liquid and to assure a substantially uniform reduction in the temperature of said fabrics; and centrifugally rotating said container at a relatively high speed to effect a removal of washing liquid from said container and from said fabrics.

3. A Washing apparatus comprising: container means for receiving washing liquid and fabrics to be washed; means for washing fabrics in said container means; means for removing liquid from said container means; drive means operable for selectively driving said washing means and said liquid removing means; liquid supply means energizable to selectively introduce hot and cold liquid into said container means; control means including sequential programming means and operable for controlling said Washing apparatus through a sequence of operation, said control means further including means for sensing the level of liquid in said container means, said liquid level sensing means being operable to a first condition at a first relatively high liquid level in said container means and operable to a second condition at a second lower liquid level, said control means being operable at a predetermined position in said sequence of operations for energizing said drive means to initiate said liquid removing means and thereby effect a partial emptying of the liquid from said container means, said liquid level sensing means being operable to said second condition responsive to a partial emptying of fluid from said container means for de-energizing said drive means and energizing said liquid supply means to introduce cold liquid into said container means whereby the temperature of the washing liquid is reduced, said sequential programming means being operable for alternately effecting operation of said liquid removal means and said liquid supply means for a predetermined accumulated period of operation of said liquid removal means, said sequential programming means being further operable for energizing said drive means to effect agitation of said fabrics in said lower temperature washing fluid.

4. A washing apparatus as defined in claim 3 wherein said programming means is inoperable for sequential advancement during operation of said liquid supply means.

5. A washing apparatus as defined in claim 4 wherein said liquid level sensing means includes a single-pole double-throw switch member operable for completing an energizing circuit to said drive means and said programming means at said high liquid level and to said liquid supply means at said lower liquid level.

References Cited UNITED STATES PATENTS 2,976,710 3/1961 Sisson et al 6812 3,055,202 9/1962; Hughes 68-207X 3,078,700 2/1963 Billings et a1 68-12 3,301,023 1/1967 Painter 6812 WILLIAM I. PRICE, Primary Examiner US. Cl. X.R. 68-42, 207, 23.7 

